text: In 1879, Schott developed a new lithium-based glass that possessed novel optical properties.  Schott shared this discovery with Ernst Abbe, a professor of physics at Jena University whose comments on glass had stimulated Schott's interest in the subject.
  Not long after Schott had completed his formal university training, he had become aware that Abbe had articulated the deficiencies in glass that was available at the time. The deficiencies were particularly acute in scientific instruments for which optical performance of the glass in lenses such as for telescopes and microscopes is paramount. Scientifically, as the magnification power of the lenses were increased, chromatic aberration became large. Chromatic aberration causes the optical quality of the visual image to become dependent on the color of the light, resulting in a significant limitation of the scientific instrument.
  In response to Abbe's scientific provocation, Schott began a systematic investigation of the properties of glass as the properties varied with the chemical composition. Schott substituted one element for another, such as borate and phosphate for a portion of the silica in the glass and substituting fluoride for oxygen.
  Schott's 1879 letter to Abbe was the beginning of a long collaboration between the two scientists.
  Abbe was already working with Carl Zeiss, an instrument-maker, on the making of glass for microscopes. Zeiss participated in the three-way collaboration by testing improved glass compositions that Schott and Abbe identified in actual optical instruments, such as telescopes.
  In 1882, Schott moved to Jena, where he could work more closely with Abbe and Zeiss.
  They created types of glass and examined their properties using silica,  soda,  potash, lime, lead oxide and 28 other elements. Lacking a theoretical basis for the work, they relied on careful and systematic observation and measurement. The addition of elements that had no direct effect on optical properties might help to correct other properties of a glass such as the occurrence of surface staining when exposed to air.
  By 1886, Schott had completed thorough investigations of structure-property relationships in glass compositions. Through these investigations, Schott discovered that the refractive index of a glass (important to its ability to function as a magnifying lens) could be disconnected from its chromatic aberration. In this way, Schott settled on a lithium-containing glass that could perform close to its theoretical limit in scientific instruments, which was a significant advance in optical instrumentation such as for microscopy and astronomy.
  By mastering the process of small-scale melt-stirring, Schott was able to create a homogeneous product, whose refractive index and dispersion could be exactly measured and characterized. Through systematic experiment, he applied this to the creation of an array of different glass types. Based on his experiments, Schott worked with A. Winkelmann to develop the first composition-property model for the calculation of glass properties.